The Puerto Rico Trench is a tectonic plate boundary where the North American Plate slides by and descends under the Caribbean Plate. Although much of the trench lies within the United States of America's Exclusive Economic Zone (EEZ), surprisingly few surveys have been conducted there during the past 25 years. This data set is a grey toned surface model image product derived from a process using multibeam bathymetry and acoustic-backscatter imagery data collected during the U.S. Geological Survey (USGS) science cruise 02051 in collaboration with the National Oceanic and Atmospheric Administration (NOAA) Research Cruise RB0208 from 24 September to 30 September 2002, Leg I of III. (Leg II and III: 20030218 to 20030407 and 20030828 to 20030904, respectively).

Horizontal positions are specified in geographic coordinates, that is, latitude and longitude.
Latitudes are given to the nearest 0.000010.
Longitudes are given to the nearest 0.000010.
Latitude and longitude values are specified in Decimal degrees.

The horizontal datum used is D_WGS_1984.
The ellipsoid used is WGS_1984.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257224.

This multibeam bathymetric image can be used in Geographic Information Science (GIS) to provide better perspective viewing and advanced analysis of geologic conditions in the Puerto Rico Trench. Remotely sensed features in the trench are studied and the information learned can be used to discern cause and effect of natural hazards such as earthquakes and tsunamis.

The processing of data from multibeam bathymetry and acoustic backscatter started with the collection of raw data imagery that were converted using Caris 5.3 Hips Sips software. The continued processing of data entailed reviewing and editing it with Caris Swath Edit, followed with Caris Sub Set mode editing. Both editing processes allowed the hydrographer to eliminate data points that were considered artifacts or out of context with the immediate benthic area. After editing, the weighted mean grid was re-generated with a grid resolution (s) from 300 to 30 meters.

This image was created from a weighted mean grid, referred to in process step one, regenerated to 150 meter grid resolution (NW sun illumination) using available on-board research vessel image processing tools.

The palette tool color mode menu, was optioned to maintain a lustrous background for the image. This type of background allows an option for transparency available in most GIS applications; when enough sheer was provided for geospatial object placement in respective coordinate positions, relational perspective views are available for useful GIS modeling of various data collected during the Puerto Rico trench science survey.

Although these data sets are used by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Geological Survey (USGS), no warranty, expressed or implied, is made by NOAA or the USGS as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by NOAA or the USGS in the use of these data.

This image is available as a GEOTIFF image with an accompanying world file. To utilize this data, the user must have an image viewer, image processing or GIS software package capable of importing a GeoTIFF image.